Project 2. Spatial Attention and Working Memory The goal of the program project is to study hierarchical levels of neural processing and cognition in order to identify the specific underpinnings of cognitive deficits in children with several neuro-developmental disorders (developmental language impairment, early focal brain damage, high-functioning autism, Williams syndrome). Project 2 will focus on spatial attention and working memory, cognitive domains that are essential to other higher-level functions such as language and social communication, and thus might mediate the impact of lower level deficits (e.g., basic sensory processing) on more complex functioning. Alternatively, this might be the first level at which deficits occur in some of these disorders. The general goals of Project 2 are: 1) to determine whether spatial attention and working memory functions correlate with brain regions associated with supramodal spatial attention and working memory in both typical and atypical pediatric populations, 2) to identify differences in spatial attention and working memory capacity in children with neurodevelopmental disorders, 3) In collaboration with projects 1, 3, and 4, to study the relationship between spatial attention and working memory competence and both more basic and more complex perceptual and cognitive functions in typical and atypical populations. Behavioral tasks will assess spatial attention and working memory in both auditory and visual modalities. Brain MRIs will be analyzed using quantitative measures of specific regions of interest as well as diffusion tensor imaging to study integrity of white matter pathways. The relationship between these structural measures and the behavioral measures of attention and working memory will provide important new information about the brain bases of cognitive dysfunction in the children with developmental disorders in our study. The results of this study will additionally provide new insight into the most appropriate points at which to aid early diagnosis, and pave the way for studies in which early interventions can target specific areas of deficits in order to achieve the most effective remediation.